FNB, the dinosaur of banking. Holding onto customer funds without cause.

FNB's inefficiency and terrible customer service putting my good credit score at risk. I get paid from a customer overseas, FNB has actually admitted to trying to find a way to send that money back to my customer before releasing the payment into my account. For the last 2 years I have received the same payment from the same customer, no problems. Just lately, FNB has decided they would prefer not to release my funds. What right does FNB think they have over these funds? Is it easier for them if I just move the account to a bank that can actually handle Forex? Unfortunately, this is one in many ways FNB is loosing business, they already lost my home loan application to Standard Bank as well as a car loan application to Nedbank. Does FNB just not want to stay open or are they running out of money that they want to hold my money captive for as long as possible?