HSBC Appalling, & treats all customers like criminals

I've been with HSBC for over 25 yrs now. I have a personal account, a business account and a overseas account. I tried opening an international currency account as my business is now international - my clients in SE Asia, Middle East, US. I don't have a massive turnover, it's fairly modest, but not small. Virtually all my transactions are electronic and auditable. Cash transactions are for petty cash purchases and limited to no more that a few hundred a month (if that). HSBC International wouldn't believe any of the documents I sent, wanted me to prove where I got the money from (even though my local HSBC bank I ban with is next to the major oil operator I work for). Nothing untoward I assumed - no - it was not enough. If they didn't believe what I sent, then all they had to do was walk 50 yds, come into my employers office (which employs over 5000 staff here), speak to me, speak to HR, look at my pay slips. Everyone in HSBC here knows the company - BUT some an* l person in 'Head Office' wants more proof. All I get from customer service is 'email this customer service department here', but essentially all that happens is that you get to speak to a new person, where the process of filling in the same form you filled in before starts again. Since it's been more than 3 months, I've decided when I am back in the UK to transfer my business away from HSBC, and eventually out of the UK if I can. The problem with HSBC is that unlike other industries, we get independent competent persons in to review/audit companies/projects on a sampling basis to ensure that it looks in principle to comply. It's impossible to audit everything since nothing will get done. My advice is now, avoid HSBC, it's the world's worst international 'local' bank. In fact, avoid the big 4 in the UK, take your money out and stick it under a mattress..if they don't want your money, s*rew them !