Noisy construction work under apartment, want to move out but landlord refuses to refund deposit

Noisy construction work under my apartment lasts for 5 months, asked landlord to reduce rental price - refused. Now i have no more patience, want to move out as soon as possible, tenancy agreement signed for 2 years ( break clause: the tenant should rent premises for at least 13 months). Following the contract I'm supposed to stay in the apartment for more 2.5 months.

Landlord proposed to find a replacement tenancy but i have to pay:

1) agency fee for find a new tenancy (50% of new rental)
2) stamp duty fee of the new tenancy agreement for landlord

And if they are unable to find someone to take over, forfeit of whole two months holding deposit.

I don't want to spend any more money on that place, because i already bought some new furniture for the apartment that stays after i leave plus i was suffering this noise for almost 5 months. Is there a way out in this situation? ( I want to get back my deposit).

It's is not written in the tenancy agreement, but i found that one of the implied covenants of the landlord is: a) tenant to have quiet enjoyment of the property. Maybe i can refer to this covenant?

Thanks for any help