Renewal already in can I fast track instead

Hi, I’ve put three child renewals in (one sent 15th March to Durham 1 sent 26th March Durham and 1 sent 26th March to Corby) I made the mistake of telling my autistic son what his picture was for and any given chance all day long he wants to know if he has his passport back to go away 31st May. He doesn’t understand the whole process (who does and definitely the passport office doesn’t) Can I send letters to cancel applications and book and appointment at Liverpool to do all three, to save our sanity? The three passports have been sent but no other documents I’ve read different ways that fast track can be done and don’t know which is corrrect Thanks in advance