Opel Kadett 200is Gearbox Repair

I went to unique auto Center to change my clutch plate since it was making noise when i put gear 2, when they removed the gearbox they told me that the problem is gearbox and to fix it is R4600. since they have removed it i told them to repair it. when i came to collect the car there was no difference. after three weeks it started liking gear oil. i replaced the gearbox seal but still it was liking. i took it back after three months and they promised that they will fix it. today i went to collect it and its even worse. they took it for three days and did nothing to the car. their service is poor very poor especially after you have paid them----never go and fix or service your car there