PRE APPROVED AND LOANS UNTRUE

I cannot understand FNB. I am always receiving pre-approved for loan information. I had a personal loan of R50000 which I paid off almost a year early. I owed on about R300. My husband and I wanted to buy a trailer with the money from a policy which pays out end January. We found one and were about R130000 short. I asked the local branch for a top up on my loan. They offered me a consolidated loan for R140000. In the meantime another offer for the trailer came in and the seller said he would give us a week to raise the money. I was covered as I had just agreed to a R140000 loan. When the loan came through it was only for R10000!!!! I have tried to get someone at FNB to assist, spent hours on the phone and all I get is you have to wait 28 days to apply again. Why when Sent through the incorrect amount. We have been put through to so many departments, run out of airtime, but no assistance.