That is the problem with NEC3: what is the effect of the compensation event if the PM fails to respond in time ? And it is why in NEC4, they introduced the "treated as accepted provision" if the Project Manager does not respond within the 2 weeks and then a further one week after a reminder notification from you.
Having said that, if the PM does not get back to you, then it gives you some strength in any argument when you wanted an action by the PM, Employer/Client or an Other and the PM does not explicitly rule it out by not accepting the programme. You then proceed on the basis that they will and the PM then informs you that you want get the access, information, Employer supplied item etc. by then. As a result, you say 'I have now incurred this cost etc.'
If the above is equates in some way to your situation, you should still give an early warning if you are not going to notify a CE.