Truworths Credit Increase!!!!

I am a client of truworths paid my account, always they decreased my limits!!! Made online payments that was a problem!!!

Called Truworths stating to them i want ro buy a cellphone and need a limit increase told me no wena , My salary is over R70 000 and cant get a limit increase????? This is all store account i have!!!!! Will close it, if not helped. My friend doest work but he have R35 000 credit will let them investigate this