Even if you change your old number to a preferred one, you can't avoid those third party advertisements.
This is how the process works!
The 'new' system can generate random set of numbers depending on the number category you applied for, these are;
a.) Normal - randomly selected by the system. That's a 550php of charge as service modification fee.
b.) Easy or Preferred - numbers with repeating digits for 'ease' of remembering, will cost 5,500php + 550php or;
c.) Golden - numbers that is believed to have 'lucky' digits in them. That's 11,000php + 550php (Yeah I know..)
Now, you'll be asked to choose what number category you prefer since this will the basis of the representative on what random set of numbers he/she will generate on the system and will be the basis of the system to generate corresponding modification fees.
PROTIP: you can ask the representative to give you all the possible number combinations so then you'll get to choose at least the change to your liking.
About recycled numbers..
I disagree that all of the numbers are recycled, though it's highly probable that the number that was applied for was already been 'used' before (read: there's a number pool system. An account once terminated, the number will be unavailable for certain period of time. Once detected 'clean' by the system, it will be pushed on the number pool and is ready to be picked.) Rarely we received calls from subscribers that complaint about getting unsolicited texts from their newly acquired number. Most of these cases if found valid however, is resolved with an offer to change the number depending on the category it was in and waive off the corresponding modification fee.
Visit the nearest store for validation and we'll gladly help you out.