Barclays bank always deny me a current account and now bought Tesco and decreased my limit in 2 days.

So in short about 5 years ago I applied for a Barclays current account, they gave me it then immediately shut it down. I went into the branch opened one then they immediately shut it down. Went to the Ombudsman and he said basically barclays have the right to not give me an account if they don't want to. I had a Tesco credit card for 5 years all well and good they kept upping my limit, I pay it off every month etc. Then Barclays bought Tesco got an email on Tuesday and was like oh great these lot, by Thursday they decreased me by £2000. John lewis recently just upped my limit. So I want to ask is there any particular reason barclays will have a grudge against me?

I have bank account(lloyds) I earn 50k a year. I have good credit, previously had a mortgage(natwest). People offer me loans and I have credit cards. I have never had a barclays account, I've never defaulted with associated banks. I don't think I've been with a sister bank. The Only thing I can think of is my brother gone done for fraud 10 years ago. But I was like 20 at the time and didn't even live in the country. Anyone have any ideas?