The law is an ass.
I can envision the scenario...if you even get a live voice, you're gonna have to wait until some publik employee gets off break to come get you fixed up. My bet: 45 minute process.
There is a simple reason for a law preventing selling of tokens outside of authorized outlets and that is that tokens are stolen by employees, sold for 25 cents on the dollar to a fence and the the fence then sells the tokens for a profit to riders. In Boston there are often pan handlers willing to sell tokens for a discount to passersby knowing they are on their way to the "T". It is no accident they have a cup full of tokens.
BTW, in my misspent youth working at an amusement park, the same scam was the major way to promote oneself and set ones own wage. All one did was to not tear ride tickets in half, save them in a safe place, deliver them to your girlfriend who worked in a ticket selling booth, and have her sell them instead of the park's tickets whereby pocketing the ill gotten gains. That is why most parks have gotten rid of the ticket and use other methods of payment.