General advice on internet / network service and number change

Update: Still unusable. The connection is all over the place and today it's around 11k/s and so wont even load web pages. I am having to use my old GiffGaff account to connect. At night it can go up as fast as 5mbs. When I am in another area of the city it can go as fast as 20mps on a speed test, so its certainly an issue with the mast in my area. What's confusing is why does it go up late at night ? The network status still says fixing an issue in my area, that did change to "no issues detected" for a day, but the connection was still poor. Now its gone back to saying they are fixing an issue in my area. I am starting to think this will be the norm unfortunately, and so might have to look for another network provider. A shame as I like Smarty and the speeds are really fast in other areas, just not right where I live 😞