i got the sms and accepted the offer. Still they need up to ~5days for it to be updated   

This is normal procedure when want to change the package speed. You will have a few times of interruption, in your account will update new package soon. Speed upgrade first then new package will be changed. Did they told you about the next bill?

They switch from their side first. If failed many times then tm technician will come to your home for double check what is going on. The worst part, my friend experience tm technician exchange old btu to new one because it's failed for reconnect back with auth got problem, the tm server side make a minor mistake that dragged for two weeks to settle the problem. Why? first, he need to use for normal unifi package then tm will switch to real deal package for him as deal during he applied through tm point. 1 week use for normal package and another week for switch package. Second, during that time of upgrade two weeks have a public holiday. After a few argument, then he finally got his package. So, blame on tm remote side ya. Make a tiny mistake, then drag many days without said sorry.