FNB Share Investing is disappointing

2 days in a row same problem repeated and i would like to believe FNB is using my money without paying for it. I placed an order to purchase some shares on friday last week and was not executed and my money had left the account. Monday i checked for the money and was still not there and still order was not executed. I phoned share investing and they attributed the problem to IT, my money only reflected in the afternoon Monday. I placed another order Tuesday today in the morning to purchase money left my account but order was not executed despite the share i intended to purchase going down from 5.60 to 4.60. Phoned share investing they say they will find out until end of day there is no response and my money is not in my account. This is a case of bank using my money to purchase low and they sell high and return the money the following day. I am seriously disappointed that issues that involve money the bank does not see the urgency in which they must respond to cases. I filed a complaint *** but still no response. This defeats the purpose of investing, i require a reimbur*****t to my loss