Above tips are very usefull but i would like to add something more
They tell you that you getting this all features and extra min everything for free and you get happy even when you call back they tell you the same thing...its not even csr fault because they tell you exactly what they see..so When you get free features and discounts .. ask them following things its few but very important
Date of when discount comes off from plan
Features that how long this feature is free for and what date its coming off ?
Take Agent Name and Number
Also note the date and time when you make this deal.
Whatever information they gave you on phone and you think date and discounts are right tell them to put this all in memo with dates and they have to put it as per your request and tell them that you will call back to make sure that what you put in memo..and if you call back any csr will read it to you if u ask for it they cannot deny
After deal check your INVOICE check all features that u r getting that u asked for, cuz in my past 4 yrs exp ppl dont check invoice and they under impression that they getting everything they asked for for free and if they see invoice by mistake after 1-2 years..they come back crying to dispute charges for last 1-2 years..so u wait 2-3 hrs to go into hassels and its not gurantee that u get refund for 1-2 yrs. You have to understand that CSR are human too they make mistake..and you have to work along too get the right stuff
After your first or 2nd invoice if you think that u r not getting u promised then call them right away dont wait because Bell Dispute policy is 3 months if more then 3 months you have to go thru supervisor..wait on phone like hours and other hassels so if you have time u can do it..if its under three months and memo is right ..they will give you refund and also the features and probaly something more for free as well
Hope those tips are helpfull if you follow those then u wont have any problem with any carrier ...