This isn't really a bug though at all is it, so maybe take the MASSIVE BUG out of your other post, this more comes down to laziness your side and want to do less work your side.
XC original had exactly the same issue and this isn't a bug with CKMOD and it is because of people like you
cesarkrespo was to give up. All the php code for packages does is take the expire date in table and then add whatever time you have set that package to be and then add the number of connections.
If you don't want your resellers to take the piss, and maybe you should have better control over your resellers that you can trust don't create a package with multiroom on it or a package that just adds more connections.
If you multiroom on our service as a reseller you put a ticket it in, we manually add it and then take off the credits ourselves so i suggest you do the same if your resellers are treating you like a mug.
Otherwise feel free to suggest some php code, as you would have to write a lot to cover everything.