Samsung S10 plus

I have a contract with cell c , got the samsung s10 plus , i have been constantly having signal issues whereby i have taken the phone to cell c eastgate and some settings was changed but to no avail, i am literally now frustrated and want a way forward, incase of emergency what use is it to me to have a phone that always has signal issues , is the cell c network so poor or is there a problem with my phone , kindly assist