UK visa after refused entry into India [closed]

I'm a Bangladesh citizen and in 2012 I was refused entry into India. They told me I must wait 60 days between visits. Oddly, a friend on the same flight with the exact same situation was let through. I returned 7 days later when this period lapsed without a problem. I have traveled to India 30 times since.

I am a frequent traveler to the UK for pleasure and currently possess a 10-year visitor visa which expires next month. I have traveled to the UK 9 times within that period for short visits. In the last 10 years, I have traveled to 15 countries including 6 trips to the USA and 2 to France.

I have a business in Bangladesh and I am confident of strong ties--I can't even consider moving to a different country.

The UK application asks me if I've ever been refused entry to any country. I have. I understand all applications are judged on their merits. However, I was told I no longer qualify for a NZ visa because the refusal means I have "serious character issues."

Bangladesh is considered a high-risk country for UK visas with a high refusal rate. How should I go about the application process? Is there anything I should pay special attention to? Does the entry refusal deplete my credibility?