Please Advise what to do

I have expressed my complaint to McDonald's on Facebook and have yet to receive any apologies or solution to my concern nor complaint. I live in Atlantis about a 20min drive from McDonald's Malmesbury. This is the 3rd time ive experienced this and 1st time i am officially logging a complaint. I always purchase 2 x jalapeno double and/or double chili cheese meals for me and my wife from the Malmesbury McDonald's and upon opening th food parcel at home we have only a single patty on our burgers. The disappointment and sad feeling is becoming unacceptable and we are beginning to lose our trust in McDonald's. I do not know what to do as i feel i should not be taking the burgers apart everytime i order a meal just to check if my burger has 2 patties on. If anyone can assist me because i feel i have been ****** by McDonald's with those 6 meals already. Please Advise what to do.