This offer is sham. I loaded up 299 in Phone Pe account. Then went to MyJio app to do a recharge of Rs 399 and then selected Phone Pe account. The app showed 399 - 50 (Jio Voucher) + 299. Which meant that Rs. 50 was shortfall. So this stupid offer is only for fake advertising. I went ahead with it anyway because I wanted double data (I am not sure I will get it because even that seems to be sham)
So I again transferred 50 to my Phone Pe account and then the recharge was successful on My Jio app.
Phone Pe gave me Rs 10 cashback because it was my first transaction.
^ I think you shouldn't have loaded up the PhonePe account first, cause the cash back is applicable only for the amount paid net of wallet balance, so since you paid only Rs 50 using the methods other than wallet balance, you got only 20% of Rs 50 as cash back ie Rs 10.
Payment to be made through BHIM UPI, Debit Card, Credit Card within the "PhonePe" option on Jio.com/MyJio checkout.
For users paying through BHIM UPI, cashback will be valid only if the transaction is processed through "@ybl" VPA handle or through PhonePe linked bank account or complete the transaction within the PhonePe app.
Offer not valid on Wallet only payments. In case of partial payments using wallet balance and UPI/Cards, only the amount paid using UPI/Cards will be considered for the offer.
No idea if i missed something, Rs 100/- is cash back, no where the offer mentioned it will 299/- or 349/- to recharge, which i also thought initially. However when recharged with 399/- via PhonePe i received a cash back of Rs50/- in my PhonePe account(6-8 months old PhonePe user) and Rs50 voucher for next use. I recharged 5 days before they announced Double Dhamaka Offer, but additional data is getting credited as ADD ON APP Data once they announced this offer. Looks like all recharges done in the month of June is covered under Double Dhamaka Offer, suddenly Double Data looks quite a lot now, browsing goes on till you require, using approx. 2.7GB-2.8GB daily now.