Cashback seems to have vanished........

[#1]

Hi Plus Net,
I've been a customer since November 2014 and have yet to receive the e-mail regarding my cash back.
I contacted Customer Services in regard to this last week and was assured my email would take 24-48 hrs to come through because they would re-send it. I have checked my emails and spam folder yet after a week no e-mail has been received.
Last week I was on the phone for over 30mins on my lunch break at work, I can't keep ringing up to be on the phone just to ask for an e-mail which it seems likely I would never get. This was part of the deal on signing up to Plusnet and I am very unhappy that I still have not received this email.
If you could sort this issue out, I would be very grateful
Regards
Will

[#2]

Morning williamgostling - Welcome to the forums.
I've had a look at your account and checked with our marketing team regarding this. I can confirm that an email was sent to email address on your account on 03.12.2015.
I can see that you called last week to question the location of the cheque and was advised a new email would be sent. Unfortunately this isn't the case. The email containing the redemption link has now expired and a new one cannot be sent as we are out of the 90 claim period.
Unfortunately we will not be able to process the cashback cheque because of the above reasons.
If there are any other queries you may have, please let me know.

[#3]

I have called numerous times over this issue, only to be kept on hold way more than necessary and having to give up on the call due to running out of time, we did wait patiently for the cheque to be sent, seeing as there seemed to be so much difficulty in your company sending them out. 
I did call last week and spent over my lunch period to finally get some information as to where the cashback was, I then waited another week for an email to be resent, as was advised by a member of staff.  I then sat on your live chat, thoroughly discussing the procedure and was told that we would receive a cheque by 21st May for £75 which was the cashback deal at that time.  This means that your message completely contradicts that.
If we receive the cashback cheque as promised, then we will be quite happy, as we do have the conversation transcript, thankfully, as it does seem that your company makes things up as you go along.  However, if we do not receive the cheque then we will be taking this further.
There was at the time, cheaper deals with more cashback, but we decided to go with yourselves to give your company a chance at providing a service after being with Sky, who I now wish I had never left.  I actually can't believe the amount of complaints about people not receiving their cashback, severely late or not at all.  You would think that this was to do with insurance claims or people getting something for nothing, this is your advertisement, your companies decision, your marketing department ploys, to pay out cashback to new customers, which you then seem to want to find a way to get out of, while your customers continue to pay a monthly fee to yourselves.
I have dealt with many companies over the years and also regarding cashback.  I have never dealt with such an incompetent company, that informs 'customers' of so many different stories, there seems to be no training to centre staff, causing customers to ring up over and over again and waste time to claim cashback which is rightfully theirs and should be given without people having to contact yourselves numerous times and jumping through hoops, this was your deal when they signed up to be your 'customer', which they continue to pay monthly bills as your 'customer'.