I'm in the midst of writing a letter to a dcfamily to let them know of a fee increase for next year, as well as giving them an updated version of my handbook and contract. It was in my previous handbook that every year i will be giving this to them so it shouldn't come as a surprise (the handbook, not the fee increase).

Anyways, in my letter about returning the contract etc... I wrote the following:

The signed portion of the Handbook and the Contract are due back to me by December 21, 2012 at the very latest. Failure to return the signed portion and the contract will be viewed as your notice of termination, although normal procedure is still required as well.

I dont want them to terminate, but want to get across that I seriously need them to read it and give the forms back.
Is this too harsh? Can I word it in a better way??
Any input is appreciated.