Charged for router postage £6.99

[#1]

Hi - I recently rang up to renew my contract and I explained about connection issues over the last year (having to restart the router many times). I was sent another router and was told I needed to ring up to get the postage cost back.  I have been charged. Is this right please?  I hate ringing most companies up and holding.  Why couldn't there be a note on my file to take the charge off my next bill?  Could this be done without me needing to ring up please?  Thank you.  

[#2]

Thanks for your post @Julie123

I've done that for you now and you'll see a credit on your next bill to cover the cost of the postage for the router.

Let me know if there's anything else you'd need help with.

[#3]

Thank you very much Anoush - that's helpful.