Shocking service and delivery. No tracking

I have contacted TNT on numerous occasions about my lost documents !!They were supposed to arrive 28th Nov. This is unacceptable as I have been told that an investigator will be in touch and I received no feedback whatsoever. This is a major time sensitive matter and the documents that were sent can not be replaced!!!!! I am beyond frustrated by TNT services and will take this matter elsewhere and make it known how I have been serviced so unprofessionally if this is not seen too ASAP!!!!!! The tracking/shipping no is - - - - - - - - This issue needs to be resolved as it will prevent my immigration to the UK which is unacceptable.