OP, what I am going to say will draw a lot of hate, but this is my experience
just few months before my A-level, I have some serious family issue, leading to mostly B in my AL
and on top of that, I return to my Home country which have less than 10 Universities and only 20% qualified students able to get a degree
I end up doing an ordinary degree with about 60%, after I graduated, I was offer a Teaching assistant post, and I enroll my PGDE. When I have my training, my supervisor told me, it will be extremely hard for any school hire me because of my degree isn't a Hons Degree. Yet, I end up teaching in 3 different school, junior and senior before I lose hope in the system.
Then I try to shift my career and have my first MSc, result in 3.16 GPA in 4.0 system, not something bright, and a year ago I finish my 2nd MSc with 67% overall score. However, I received 3 funded PhD studentship offers, and even 1 interview from Oxford.
Examination does not always reflect how a student doing, in my year of teaching I have seen straight As student who turn out to be "not very smart", I have also seen a very smart student who only got D at best. Some student are better at doing exam, some excel in other form of assessment.
Applying a PhD studentship is not applying a job, you will spend you next 3 years working in that dept., and with those team, the supervisor is looking for someone not only have the intelligence, but also genuine interest and commitment to the project. You should draft an e-mail outlining you interest and discussion with the supervisor, it may not guarantee you an interview, but you will gain valuable experience as well as leaving a good impression to the supervisor