There are got some awkward sentences sprinkled into the story here and there, like:
Its not fair, and she already has 7 points on her license (that Yousef doesn't know about).
Ria though, like her was an "incomer" from London, and like her, of Asian heritage.
Echoes of her dream-fuck cascaded through her blissfully wiping out, at least temporarily, the disabling hangover she had felt when she woke up.
These sentences have unnecessary pauses in them, breaking up the flow and making them hard to read.
There's also quite a bit of bad punctuation, for example:
Somehow, though every head still turned towards her.
She turned around and a businessman was heading to her table, "mind if I join you"? he started to introduce himself
What the fuck Jeni? I've been calling you all afternoon"! shouted Ria.
There should be a comma after 'though', and punctuation always goes between the quotation marks in fiction.
A good double (or even triple) reading would help to catch mistakes like these. A trick that might help is reading more complicated sentences aloud, or at least aloud in your head. Commas go where you pause naturally.
Slightly less nitpicky, one thing that might limit appeal is that you've put 'vampire' front and center. Unfortunately, in this day and age, that brings to mind Twilight's Edward, not Bram Stoker's Dracula, and many people--no, let's call it what it is: many
guys will refuse to engage with a type of story that modern culture has firmly coded 'for teenage girls'. Weirdly, the story doesn't seem to feature anything that we'd classically recognize as a vampire, at least not in the first 15 chapters, so unless you're planning to feature Proper Real Vampirism (drinking blood, photophobia, vulnerability to silver, etc), you could very easily replace the word 'vampire' with another supernatural creature, possibly of your own invention, and avoid the whole problem.
I also think the introductory chapters are a little sluggish. I like that you switch to a flashback to portray the evening out, but it follows a bunch of exposition that I don't think the story really needs. Paragraphs 2, 3, and 4 of the first chapter are all unnecessary. Expand the cop scene a little (what does he look like? Hot? Ugly? Old? Young?), then when notices she smells of alcohol, cut to the flashback (which could use a little slimming down as well). When we return, the extortion follows naturally, and then the introduction of the monster.
