Laravel website payment gateway fix

We hired sb to fix our payment gateway system for our website but they did a shitty job, the payment gateway is flutterwave. when sb makes payments using the flutterwave gateway the transaction isnt recorded on th database and one cant see anything that they have booked. we want this redone and fixed well. We want to use the flutterwave standard gateway to process payments. our site deals with bookings and reservations. The front end uses angular, already the functionality to add the api keys from the backend he had added it but maybe you might need to review it