Thanks for getting in touch @robquick I'm sorry to see what has happened and you're missing your referral credit as a result. Unfortunately when re-adding the referral, the system would treat this as a new referral as opposed to an existing referral and if we're past the 90 day window from when the account was signed up, it likely won't allow us to re-add the referral.
This is under investigation however as a workaround in the interim, I'd suggest we add a recurring discount to cover the missing referral credit, which we'd manually renew if that referral is still with us/meets the rules on referring.
Leave this with me to look into further tomorrow and arrange.
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