MWEB Fibre bad service

I've been calling you, staying on the phone for more than 40mins just for the call to be dropped when you answer. You made an error on your side by assigning my 100Mbps line to someone else, I was capped on 50Mbps for 5months you've billed me for not receiving the speeds I should. No you are not responding on my queries that I've logged It's been more than 10 working days. You need to credit my account, the service is poor