I submitted my cashback claim at the beginning of Feb with the sales receipt and a photo of the serial number as required.

I received an email back on 2 Feb confirming the receipt of the cashback application.

I have checked numerous times and each time the status shows they are awaiting validation and yet again in the last few days so I submitted a customer service request for an update, response from Sony:

With reference to your cashback participation for the Sony SEL55F18Z Lens, we would like to confirm that the cashback for your claim is being validated by our cashback team regarding the reference number of xxxxxxxxxxxx and claim ID of xxxxxx.

Please click the below link to check your claim status:

https://www.sony.co.uk/promo/cashback/status 

Unfortunately, there is no specific time frame on when the claim will be validated, however, once validated, you may allow up to 28 days after the validation and your cashback will be transferred to your bank account from Link Network or World Pay, as you will be confirmed by email if accepted or if any other information is required.

29 days to validate the application seems crazy when evidence of a purchase from a Sony approved dealer is submitted and now to be told it could take a further 28 days following validation is ridiculous and unfair to customers - why can't they be like Nikon(and I suspect others) who respond in a far more timely manner.

As good as Sony products are, their customer service related to cashback handling is abysmal.

Very poor show Sony!