Wow...sorry to hear about this problem; apparently the electronic wastegate wasn't thoroughly sorted before they went into production. Of course, this is 2 reports versus hundreds, maybe thousands sold. I've owned 4 3-series cars and 1 1-series; no problems with any of them and nothing but the best treatment from dealerships and BMW corporate.
One thing I've learned, particularly after 10 years of law enforcement is that attitude is 90% of a ticket. Same applies to business dealings.
2013 F30 335i M-Sport 8AT/MPE/MPPK, 2016 228i M-Sport Cabrio 8AT