Unable to increase daily payment limit on business account.

I am a business rescue practitioner and have to make large payments from time to time but the default on the account for daily payments is R1m. I have tried various ways that FNB says that I can get the daily limit lifted, even if just a temporary arrangement but I have not been successful. They do not respond to queries and the number that they gave for business support, being *** does not work. I urgently need someone at FNB to assist me. Alternatively I have to go the branch as they are always very helpful.