Get new router for free at Unitymedia?

My parents have the problem that they just surf at their new laptops with 2.5 Mbits. You have a contract with Unitymedia but with 30 MBits (it is only a maximum of 30 MBits is already clear to me!) But not even 10% of it arrive is I find too little. From the conversion to 5Ghz has changed nothing. My guess is the old router, it's a TC7200.U

My question is whether it brings something to call Unitymedia and try to apply for a new router? Did somebody have success with that? My parents have been customers for many years? Or do we have to pay a new router from our own pocket?
How should I proceed?

They will not replace the router. For this reason, I advise you to report a defect. Just tell them that the part is getting smeared, getting overly hot, or you're thinking of something else. Then they exchange the part for free

Plug yourself by cable to the router and not wireless, how much is it?

I think I do not even have such a cable 😅

Yes, this router is probably a mean disaster in WLAN!

Here many Unitymedia customers complain:

https://community.unitymedia.de/categories/internet/question/staendige-internetunterbrechungen-beim-wlan

The thing is broken! Try the exchange via Unitymedia.

If they do not exchange the thing, then there's still a passable "emergency solution":

Buy a modern wireless repeater (for example, Fritz Repeater 1750e, which you can use well in the future) and a LAN cable (if none exist).

Here e.g. For Saturn: https://www.saturn.de/...00476.html

Configure the WLAN repeater as an access point and connect it via LAN cable with the TC7200 router (to LAN 1,2,3 or 4). Turn off the Wi-Fi in the TC7200 completely, and your wireless problems are solved.

Here are the instructions for the Fritz Repeater 1750e:

https://avm.de/...verbinden/

I read: Do not have a LAN cable?
A CAT5e or CAT6 cable is sufficient.
Here for 4 euro is 5m LAN patch cable (with matching RJ45 connector).

https://www.saturn.de/...18574.html

Then you can place the repeater optimally (increased is always good).