problems with internet

I have been a satisfied customer for 3 years. We have internwt in kpn and there have never been problems with the coverage that has been around for several months. A speed test was done (two floors) with the help of your kpn page, with the result of the lowest data transmission ... The monthly cost for a subscription is 43 euros, and the quality of data transmission is getting worse, ans sometimes with a temporary lack of internet ... We are bot interested in additional equipment for improving internet speed that you offer on your website. Please verify and eliminate the problem. Thanks