Telkom LTE WiFi with speeds of a Dial-Up connection

I have the Telkom LTE Home WiFi for the past two plus years. When I first got it we where getting speeds of 40mbps download. A year later the speeds dropped to around 15mbps, which is still good compared to the adsl speeds in the area.

But recently Telkom rolled out the mobile house phones in the area and I'm assuming it runs of the same tower as our WiFi speed has drastically dropped to around 4mbps and is almost nonexistent during peak hours. I have to switch to mobile Data to stream a simple YouTube video which wont play on WiFi even if i select the lowest quality.

I've called Telkom on numerous occasions regarding this and my call just gets forwarded from department to department because no one there has a clue as to what they're doing. If this cant be solved i'll be forced to change my service provider