very bad 8Ta signal

Hi. I have 8Ta SIM and it always has weak signal. I also have to refresh network throughout the day, because network keeps crashing. I buy lots of data and can hardly download much, because it's too slow and network keeps crashing. Most of the time at home the signal bar is on one or two bars. I mainly have all these problems in the house. The area I live in is Northpine Brackenfell, Cape Town. Please help, only other option will be to change network. I'm wasting my data on poor network signal. Tired of network crashing all the time.