Waste gate problem

Hi All,

Just into my third year of driving an Octavia 1.4tsi Elegance & just out of warranty I started to experience a problem that it has taken 3 visits to Skoda to sort out, I wonder if anyone else had this problem or has experienced the same? I did read some posts on Briskoda with similar problems but on diesel-engine cars. 

Quite a few times under hard acceleration in 3rd or 4th the car stutters with a loss of power &/or surges, on one occasion not being able to rev over 3000rpm & a second time when the engine management light illuminated briefly. The first time at the dealer 2 fault codes were indicated; the turbo boost switch & the turbo bypass valve. On the second visit they couldn't find any fault & the third time yesterday they managed to replicate the problem & diagnosed it as something to do with the waste gate. On consultation with Skoda they were told it was a known problem & there is a kit to fix it, however Allams in Epsom say they never heard of it, had never fitted the kit before & couldn't (or wouldn't) explain any further what exactly it is. They want the car for a least a day, if not 2, so I suppose it's a big engine job

Any idea's, I read that with diesel it could be the flywheel protection software to the ECU but this is a petrol engine?

Thanks for any help!