UK visa refused do to lack of economic ties in the UK. What are my options? [duplicate]

Based on advice given on the forum. I have applied and was refused and below is the wordings of my refusal word for word.

the decision

I have refused your application for a visit visa because i am not satisfied that you meet the requirements of paragraphs V4.2 (a)(e). of appendix V. Immigration Rules for Visitors because: Home Office records show that you have previously been refused a UK visa. However each application has to be accessed based on its merits using info and evidence submitted.

You are seeking entry into UK for 8 days to visit your family(MOTHER, father, bro)...who are all resident in UK. I note you also have a sister in UK.

You have stated on your application that you are employed as a business development Exec with Snug Global Services and earn ***** per month. You have supplied an employment letter to support this. I note that this letter doesn't have a named signatory. The contact email for the business is ********@gmail.com rather than an official, corporate email account. I also note the phone numbers provided are mobile numbers. A search through open sources has located an official website for a business called ******* in Nigeria, however the contact details on this website doesn't correspond with the details of the letterhead. From the information on your application form and the documents you have submitted, I am not satisfied that your employment and income is as stated. I am therefore not satisfied that your economic status is as declared.

As evidence of funds you have submitted statements of ****bank and F*** bank for accounts in your name. However you have not sufficiently documented your employment or your income and the documents supplied support the origin of these funds. I am therefore not satisfied that these funds are genuinely available for your use or that your financial circumstances are as stated.

Given the above I am not satisfied that your economic circumstances are settled and that they constituent ties that tend to support your stated intention to leave the UK.

In the light of all the above I am not satisfied as to your intentions in wishing to travel to the UK or that you will leave the UK at the end of your visit. Furthermore I am not satisfied that you have sufficient funds available to cover your costs whilst in the UK with working or accessing public funds. Your application has been refused under paragraph v 4.2(a)(e).

The copy of my employment letter was not signed by me (this was a stupid omission on my part). The original is on my file with the company.

My question is how do I show company and my employment letter is real and what documents should be submitted to address the ECO's concerns so as not to damage my credibility.

The company is registered with CAC, and the company does have an official email address which is not on the letterhead I submitted.

The mobile phone numbers was used to register the company with the CAC, so will showing company registration and company bank statement correct the wrong impression. What can the company I work for send to support my reapplication?