Sub standard phones

I am sorry for having to do this, but I see no other way, as the service I get from Checkers Hyper is of the best. I recently, about a week ago, bought two mobicell phones. Within a day, storage space ran out. I bought a memory card, but the problem persists. I only use it for whats app and email, so it is not as if I over use it. Now I sit with two obsolete phones.