I switch to Plusnet in late June this year and was told to wait for Reward email to come in to make a claim.
However, haven't received anything until now and thought it was some kind of delay due to Covid-19.
Called your customer service today and been informed an email was sent to me already with the Reward link which has expired.
It is obviously disappointing news. Although I understand Reward is one of the commercial approaches, the customer should have been made clear from the first place, how long they need to wait for Reward email before expiry. If not received, what the customer need to do.
The Reward email was possibly gone to Junk email box and it would be good to send various emails/reminder.
Not sure if there is anything you can do at this stage, but it feels like Plusnet Reward is nothing more than a commercial attempt.
The probability is very high judging by the proportion of members here complaining about not receiving the email, that it was not sent in the first place. If you search the forum for 'email not received', 'missing email', 'no £75 voucher' and similar, you will be aghast. You will also notice also that nobody mentions ever finding the email in their spam folder either.
If you are able to phone customer service again and complain, armed with this information you might get somewhere. After all, you are owed £75 which is no small sum. One would expect a responsible company to have reminded you that you had not claimed it, or made it easier to obtain in the first place, instead of having to negotiate an obstacle course, or as you have found, telling you you're too late.
If you have no success on the phone, search for posts by Overscore and you will find other avenues to explore.