Discovery bank can't trace deposit and doing nothing to resolve

I transferred $1000 to my new opened $ account on the 1st of April. On the 5th of April I enquired, and they asked me for proof of payment which I sent to Discovery bank. I have phoned many times and there are only promises with no resolution. I am going to USA and have mo0re money to transfer but can’t do this until we resolve this. Discovery bank does not care about their customers and has not have had the decency to contact me or given me a progress report. What must I do as I am leaving for the USA in 3 weeks’ time?