MWEB CONNECTIVITY - Always Drops since new package

Ever since Mweb put me on a higher up and down speed back in Aug/Sep last year I've had endless issues with connectivity. My speed in the evenings drops right down to 4.19 download and 0.09 upload. We are only 2 people in my 2 bedroom flat. I've called Mweb a number of times to rectify and in the end I use all my airtime calling them and I still have the problem 5 months later.