UK visit visa refused twice: first for funds parking, then for questionable purpose of travel. Should I reapply? [duplicate]

I am Pakistani citizen female doctor residing in Saudi Arabia with my Husband. I had applied for Business visit visa ((PLAB/OSCE TEST) to take MRCP PACES (Medical Post Graduate Diploma) exam in the UK on 02/10/15. Intended duration of visa was of 6 weeks where I showed intention of sight seeing after taking exam. Also, during my stay, I was planning to stay at my aunts so I attached her support letter (for accommodation only) along with her passport copy and house bills. I was to be financially supported by my husband during this trip as I am currently unemployed and attached his Bank statement, employer's letter and affidavit. He decided not to accompany me for the trip in order for me to have compelling reason to return to KSA. He had mentioned in the affidavit that he got recently a deposit from his employer as a compensation for vacation salary. But, I got rejected first time due to not providing provenience of funds other than monthly salary (Attached letter)

After rejection, I requested the MRCP exam controller to postpone my exam in November 2015 in order to have time to reapply for the visa. I reapplied and attached an explanation letter from my husband explaining the origins of all the deposits other than salary. He also attached all the evidences to support his claims. Also, this time my husband provided a letter from employer explaining about the vacation salary (Largest deposit). Yesterday, I got rejection again and this time the reason was that the exam is available regionally and I had to provide evidence that I applied before applying for the UK. Also, they said that I didn't attach IELTS result despite of the fact that I included the copy of IELTS* (8 band each). Point to be noted is that the visa officer was different this time and he/she didn't comment on the previous issues of providence of funds so I assume he/she is satisfied with the provided explanation/evidences.

Now, I would like to apply for the third time as I still have time provided I apply on priority basis (I applied both time on priority service). I can provide them the evidence that I applied for regional exam back in June 2015 but was not selected due to the limited seats and can reattach the IELTS, original this time.

An interesting point to mention here is that it is not mandatory first to apply regionally and apply in UK only in case of rejection. 3 of my study partners has got their visa in first attempt (from Pakistan) even though they didn't try regionally first. But, I know that each case is assessed on individual basis and we can't compare. Also, as per MRCP website, IELTS is not mandatory. It is mentioned on the website

As all assessments are conducted in English, the Royal Colleges of Physicians advise candidates that in order to be sufficiently prepared to sit the MRCP(UK) Diploma, their English language ability should be equivalent to International English Language Testing System (IELTS) Level 7.5.

However, candidates do not need to have taken IELTS or any other language examination, to sit the MRCP(UK) Diploma.

Interestingly, visa officer skipped the last part. Anyhow, I got 8 in IELTS and also attached, I don't know how they missed it.

So, I would appreciate if you can advise the following.

1. Is it wise to reapply for third time by providing the required evidence. A friend of mine told me that it is useless as their comments are baseless and they simply don't want to issue me the visa. I don't think that could be the case, right?

2. I know I will look desperate applying third time in the row. But, I would like to mention that my desperation is because I am studying for 8-10 hours daily for the past 3 months to prepare for the exam. Exam fee GBP 650 is non refundable and if I take this exam regionally, it would cost me same if not more because exam fee is double in international centers. Also, taking MRCP at international centers is difficult because of preference for local candidates.

3. I am shortening my visit this time to just 1 week as I am no longer interested in sight seeing. Would that be a problem.

4. I checked there is an option for lodging complaint. Is it advisable?

5. Why didn't the visa officer mention the second refusal comments in first refusal letter so that I could have tried to satisfy him in one go. I am afraid that he/she will now come up with some new comments. Isn't it unfair?