Discount on montlhy bill

I recently migrated from Ziggo to KPN, just because KPN was offering a discount for the first year of 50% less on the monthly bill. Guess what… I started to receive my monthly invoices and there is no discount…. I went to the website, was looking for a place to communicate with KPN, tried their BOT terrible was not able to help… Also, there was a link on the website that mentioned that the discount should be requested, went over to this link and NOT working… What is wrong with all the telecom companies in existence, they are ALL terrible…

Well going to the help I need… How do I get the monthly discount on my invoice? Any secret to that?

Thank you,

Felipe