Filter mobile phone numbers database (coding required) for certain telco/prepaid/postpaid and determine if valid for better sales

We are ,mobile contract sales people looking to target the most appropriate customers for sales. Generally we have found converting prepaid numbers to plans the most efficient method since the person is on no lock in contract. (IE if someone owes thousands or has years to go on a plan we do not want to waste our time speaking with them) We have a large database of mobile numbers and would like to filter out specific telco providers and also determine if number is firstly valid and switched on (not super important) but also develop a checker to test whether the number is a prepaid number or a postpaid number as a way to determine demographic and financial factors related to the numbers we are marketing to. For instance in australia there are 3 mobile networks (telstra,vodafone& optus), different types of poeple use each telco and its significant. The most basic way to filter them is to search the number to see what telco it orgiginaly started with but with porting in place its not the most reliable method anymore. Through experience we have good knowledge that our best customers to target are telstra and optus customers on prepaid plans given we know we can definatley give them a better offer than what there currently on. (IE we not want to waste time calling customers we can beat there price or have thousands owing on there plans still. So for instnace we need the following program/checker coded to determine if the number is infact with optus prepaid. If you go to the following website [login to view URL] you can see that all that needs to happen is for each number to be entered and attempted to be recharged via voucher etc. Thus figuring out if it is a prepaid number for us. (what we want) (this example of 1 provider) Further to this, in the future we believe it is possible to determine a number pattern for each tel co that is allocated to them. Again we are looking for prepaid numbers (which im sure a pattern exists) and if they are infact active. The most important thing is to get the coding done so we can begin checking our own numbers so at this point it is more of an it job than has to do with marketing / sms. A site like [login to view URL] can tell you the provider but ths is all i believe and it is expensive. I dont believe that it tells you if the person is on a plan or not.