Oyster refund when taking advised costlier alternative during delay

[BoundForFinalD]

usually during delay I will wait until the problem resolves so simply i will claim delay refund for my oyster.
But yesterday it was an urgent trip from Richmond to finchley road and the district line decided to have a severe delay from/to Richmond while mildmay was closed. The announcement advised us to take the SWR to Waterloo, which is costlier than any usual alternatives.
I was told by the staff that because of the delay either the charge would be automatically adjusted when touching out or I could simply claim the difference online. Of course as expected the charge was not automatically adjusted.
I was wondering if at all the difference was claimable, and if so on which page I should seek it. Is it on the general enquiry webpage?
Everytime there’s a delay it always says ticket are “accepted” on alternative routes or even buses, but it seems like if you are using oyster the extra charges incurred are not adjusted, at least as my mates have experienced.
I m new to london so your help is appreciated.

 

[miklcct]

TfL can refund any extra fare paid due to disruption on their services by calling their hotline.

 

[Watershed]

The TfL Conditions of Carriage state that if you're using PAYG, then in the event of disruption you are not entitled to a refund of additional amounts you're charged for travelling via a more expensive route.

TfL may provide you with a refund of the additional cost as a gesture of goodwill but I would not expect it. Unfortunately in these cases it is often only paper ticket holders (most of whom are paying far more than the PAYG fare) and Travelcard/season ticket holders who can actually benefit from the ticket acceptance.

One workaround for mitigating the expensive paper fares that TfL charge along most of their Overground routes is to buy to/from a station just beyond the Overground route. For example, an Anytime Day Single from Richmond to Finchley Road & Frognal routed "not via London" costs £7.00. However, an equivalent single from Twickenham, one station west, costs only £4.80 - and this would entitle you to start your journey at Richmond. In this particular example this would be cheaper than the PAYG fare via Zone 1.